Plastic bag with easy-open feature

ABSTRACT

A plastic bag having a gussetted bottom and sealed at both sides, and having special end formations for the gussetted bottom such as to provide a tab at the lower end of each side seal when the bag is packed, either of these tabs being adapted to be grasped and pulled upwardly toward the upper end of the bag to tear the bag open.

United States Patent [1 1 Goodwin 1 Aug. 7, 1973 PLASTIC BAG WlTHEASY-OPEN FEATURE [75] Inventor: Ralph C. Goodwin, Wayzata, Minn.

[73] Assignee: Bemis Company, Inc., Minneapolis,

Minn.

[22] Filed: Oct. 19, 1971 [21] Appl. No.: 190,547

[52] US. Cl. 229/66, 229/61 [51] Int. Cl 865d 33/00 [58] Field of Search229/66, 57, 61

[56] References Cited UNITED STATES PATENTS Kugler 229/57 PrimaryExaminerSamuel B. Rothberg Assistant Examiner-Stephen P. GarbeAttorney-Irving Powers et al.

[57] ABSTRACT A plastic bag having a gussetted bottom and sealed at bothsides, and having special endl formations for the gussetted bottom suchas to provide a tab at the lower end of each side seal when the bag ispacked, either of these tabs being adapted to be grasped and pulledupwardly toward the upper end of the bag to tear the bag open.

8 Claims, 10 DrawingFigures minnows new SHEEI 2 0f 2 FIG-6 FIG] PLASTICBAG WITH EASY-OPEN FEATURE BACKGROUND OF THE INVENTION This inventionrelates to plastic bags, made of polyethylene, for example, and moreparticularly to an easy-open feature for such bags.

The invention is especially concerned with what is termed a baler bag,i.e., a relatively large bag used as a master container for smallerpackages, and particularly smaller filled bags such as five and tenpound bags of flour, sugar, pet food, etc., and with such a baler bagthat is applied in stretched condition around its contents.

. SUMMARY OF THE INVENTION Among the several objects of this inventionmay be noted the provision of a plastic bag, and especially one usefulas a stretch baler bag such as above-mentioned, which has an easy-openfeature for tearing the bag open for removal of its contents avoidingany necessity for cutting such as might damage the contents of the bag;and the provision of a plastic bag with such a feature in amannerwhichnot onlydoes not interfere with the stretchability of the bagfor stretch baling, but which is also most simple and economical.

In general, a bag of this invention is made of heatsealable sheetplastic material with a gussetted bottom comprising two opposed gussetpanels each joined to a respective wall of the bag at a bottom fold ofand eittending upwardly from the bottom folds between said walls andjoined together at their topby a fold constituting the central fold ofthe gussetted bottom. The

lengthof each of saicl bottom folds is less than the width of the bag.The gussetted bottom is adaptedto unfold and lie flat when the bag ispacked. The lower portion of each wall below the level of said centralfold and the respective underlying gusset panel each have end edges ateach end thereof extending from the respective end of the respectivebottom fold at an angle thereto upwardly and outwardly to a pointspacedinwardly from the respective side of the bag and below the level of thecentral fold and these end edges are heat-sealed together to form angledend edge seals, and further have heat-sealed tab-forming edge portionsbetween said point and the respective side edge of the bag. When it ispacked, the bag has a generally rectangular flat bottom formationconstituted by the portion of the two gusset panels between said bottomfolds unfolded and lying flat therebetween, and side panels extending upfrom the ends of said bottom formation. The said angled end edge sealsextend upwardly and converge toward one another from the comers of saidrectangular bottom formationat the lower end'of each of said sidepanels, and the packed bag further has a tab at each side thereofconstituted by the portions of the bag walls and gusset panels boundedby the said heat-sealed tabforming edge portions overlying the sidepanel atthe upper end of said angled edge sealsvadapted to be graspedand pulled up to tearthe bag open along the side panel. y

Other objects and features will be in part apparent and in part pointedout hereinafter. l

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 is a view of the lower end ofa bag of this invention made according to FIG. I, on a larger scale thanFIG. 1, showing the bag in its flat condition as manufactured, andbefore it is packed;

FIG. 3 is a perspective view of the lower end of the bag as it appearswhen packed; l

FIG. 4 is an end elevation of the lower part of the packed bag; i i lFIG. 5 is a section on line 5-5 of FIG. 2 with the bag walls spreadsomewhat open to show detail;

FIG. 6 is a section on line 6-6 of FIG; 5;.

FIG. 7 is a view similar to FIG. 6 showing a modifica- Correspondingreference characters indicate corresponding parts throughout the severalviews of the drawings.

' DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. I ofthe drawings, there is indicated at. l a length. of a center-folded webof heat sealable sheet plastic material such as polyethylene. Thetwohalves of the center-folded] web are each designated 3.,Rand thecenter fold (which joins these two halves along the longitudinal center.line of the web) is designated 5. The center-folded web 1 is shown inFIG 1 as being fed forward toward the right. As-the webis fed forward, aband or stripe 7 of a rnateri al constitutinga heat-sealsinhibiting orrelease'coatiriglis applied to one .face thereof (the upper face asshown in FIG. 1) extending longitudinally of the web spaced from butadjacent the center fold 5. The heat-seal-inhibiting or release materialmay be a commercially available polyamide'based ink, which may beunpigmented so as to be clear and invisible on the polyethylene, orwhich may be pigmented and printed as part of a brand pat tern on theweb.

As the web is fed forward, and after it has been printed with the heatseal-inhibiting stripe it is provided with a gussetgene'rally designated9 along its closed longitudinal margin (the margin which includes fold5). The gusset is formed by tucking in the margins of the two halves ofthe web and reversing the fold 5 as shown. The two folded-in portionswhich become the two opposed panels of the gusset are each designated1 1. Each of theseis joined to the respective half of the web at a foldline 13 and the two gussetpanels Ilare joined together along thereversed fold -line,.S. The

of one of the gussetpanels ll). Theiparticulars of this width will bespecified later. The spacing of the stripe from the original fold 5aissuch-that whenthe gusset is intucked,the stripe is located on thatsurface of one of the :gusset panels 11 whichfaces theothergussetpanelll (thisis the surface of the gusset panel which faces outward when thegusset unfolded flat), with one edge 7a of the stripe extending allongthe respective fold line 13 andthe other edge7b of the stripe spacedoutwardly (downwardly) from the reversed central :fold

Following the intucking of the gusset 9, the web 1 is heat-sealed andsegmented on lines indicated at in FIG. 1 extending transversely of theweb spaced at bag width intervals to form individual bags B each havinga gussetted bottom provided by the gusset 9 and an open mouth oppositethe bottom as indicated at 17. As will be understood by those conversantwith the art of manufacturing plastic bags with heat-sealed seams atboth sides, the two opposite walls, each designated 19, of each bag areheat-sealed together on each side of the line 15 of sealing andsegmenting to form a bag side seal designated 21. In accordance withthis invention, the web 1 with the intucked gusset 9 is also heat-sealedand segmented on lines such as indicated generally at 23 in FIG. 1leaving notches such as indicated at 25 in FIG. 1 at the end of eachline 15 toward the gussetted margin of the web. This heat-sealing andsegmenting on lines 23 is such that the length of each bottom fold 13 ofthe bag is less than the width of the bag. It is also such that thelower portion of each wall 19 of the bag and the respective underlyinggusset panel 11 each have end edges indicated at 27 at each end thereofextending from the respective end of the respective bottom fold 13 at anangle of 45 to the line thereof upwardly and outwardly to a point 29spaced inwardly from the respective side of the bag and below the levelof the central gusset fold 5. These angled edges are heat-sealedtogether to form angled end seals, and it will be observed that thereare two such seals designated 27 at each end of the bag bottom, one infront and one in back. The heat-sealing and segmenting on lines 23 isalso such as to form heat-sealed tab-forming edge portions 31 incontinuation of seals 27 extending laterally outward to the respectiveside edge or side seal 21 of the bag. Each bag wall 19 and therespective gusset panel 11 are heat-sealed together all along theseedges at 27 and 31 from the end of the said bottom fold 13 out to therespective side edge or side seal 21 of the bag, but it will be observedthat the two two-layer portions at the bottom of the flat unfilled bag,one constituted by one gusset panel 11 and the overlying lower portion19a of the resepective wall of the bag and the other constituted by theother gusset panel 11 and the overlying lower portion 19a of the otherwall of the bag, are wholly free of one another due to the interpositionof the heat-seal-inhibiting material at 7, preventing the heat-sealingtogether at 27 and 31 of the stated twolayer portions.

As shown in FIG. 2, the lines of seal 31 are inclined slightly upwardlyfrom points 27 outward to the lower ends of the side seals 21 of the bag(preferably at an angle of approximately 10 to the horizontal). Thewidth of the stripe 7 is such that its upper edge 7b is at a level belowthe level of the lower ends of the bag side seals 21 (and above thelevel of points 29) so that full sealing of the side edges of the bag at21 all the way down to the lower ends of the side edges is assured. Thecritical factor here is that the upper edge 7b of stripe 7 terminates atthe lines of seal 31 between points 29 and the lower ends of the sideedges of the bag so that there is no interference from the stripe 7 tothe formation of the bag side seals 21 (see particularly FIG. 6). Analternative and equivalent arrangement is shown in FIG. 7, wherein thelines of seal 31a corresponding to lines 31 are horizontal (e.g.,parallel to the bag ends) instead of being inclined like lines 31, andfor purposes of non-interference with the formation of the bag sideseals 21, the stripe 7 is formed with gaps such as indicated at 33 inFIG. 7 at the location of lines 15 in FIG. 1 whereby the upper edgeportions 7b of the stripes which remain when notches 25 are formedterminate short of the side edges of the bags.

The construction of the bag with the ends of the bottom portion formedas shown and above described is such that when the bag is packed (e.g.,stretched, loaded with a plurality of smaller packages, and allowed tocontract around the smaller packages), it has a generally rectangularbottom formation such as indicated at 35 in FIG. 3 constituted by theportion of the two gusset panels 11 between the bottom folds 13 unfoldedand lying flat between these folds 13. The walls 19 of the bag extend upfrom the bottom folds 13 at the front and back of the bag and sideportions of these walls form generally rectangular side panels indicatedat 37 extending up from the ends of the rectangular bottom formation 35.The inclined seals 27 at each end of the rectangular bottom formationare angled (at 45) and converge toward one another upwardly in the lowerendportions of the side panels 37 from the corners 39 of the rectangularbottom formation and these seals in conjunction with lines 41 of fold incontinuation thereof define a generally triangular section 43 of eachside panel having as its base the respective end 45 of the rectangularbottom formation 35. Further, at the lower end of each of the side seals21 centrally of the width of each of the side panels 37, the bag has atab 47 constituted by the portions of the bag walls and the gussetpanels 11 above the lateral tab-forming seals 31 overlying the upperportion of the respective triangular section 43. 1

Each tab 47 forms a pocket at the upper end of the triangular section 43for upward reception of one or more fingers of the hand for grasping thetab to pull it upward. By pulling it upward, the bag is readily tornopen on lines starting at points 29 (where the stress caused by thepulling is concentrated) and continuing up the side panel 37.

FIGS. 8-10 illustrate a modification in which each triangular tab 47 hasan extension 49 extending downwardly therefrom adapted to be morereadily grasped and pulled to tear the bag open. To form theseextensions, the heat-sealing and segmenting at 23 is such that the edgeportions from points 29 out to the side seals 21 of the bag have aportion 31a extending downward from the point 29 and a lateral portion31b extending from the lower end of portion 31a over to the side seal21. The heat-seal-inhibiting stripe 7 is applied with gaps such asindicated at 51 to provide for formation of the side seals 21 all theway down to the lower ends of the tab extensions 49.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

1. A bag made of heat-scalable sheet plastic material having a gussettedbottom comprising two opposed gusset panels each joined to a respectivewall of the bag at a bottom fold and extending upwardly from the bottomfolds between said walls and joined together at their top by a foldconstituting the central fold of the gussetted bottom, the length ofeach of said bottom folds being less than the width of the bag, thegussetted bottom being adapted to unfold and lie flat when the bag ispacked, the lower portion of each wall below the level of said centralfold and the respective underlying gusset panel each having end edges ateach end thereof extending from the respective end of the respectivebottom fold at an angle thereto upwardly and outwardly to a point spacedinwardly from the respective side of the bag and below the level of saidcentral fold and heat-sealed together to form angled end edge seals,said opposed gusset panels being free from one another between saidbottom folds and said points and further having heat-sealed tab-formingedge portions between said point and the respective side edge of thebag, said bag, when packed, having a generally rectangular flat bottomformation constituted by the portion of the two gusset panels betweensaid bottom folds unfolded and lying flat therebetween and side panelsextending up from the ends of said bottom formation, with the saidangled end edge seals extending upwardly and converging toward one anoher from the corners of said rectangular bottom formation at the lowerend of each of said side panels, and further having a tab constituted bythe portionsof the bag walls and gusset panels bounded by the saidheat-sealed tab-forming edge portions overlying the side panel at theupper end of said angled edge seals adapted to be grasped and pulled'upto tear the bag open along the side panel.

2. A bag as set forth in claim 1 wherein the bag has heat-seals at bothsides.

3; A bag as set forth in claim 1 wherein said angled seals are inclinedat an angle of 45 to the line of the bottom folds.

4. A bag made of heat-scalable sheet plastic material having a gussettedbottom comprising two opposed gusset panels each joined to a respectivewall of the bag at a bottom fold and extending upwardly from the bottomfolds between said walls and joined together at their top by a foldconstituting the central fold of the gussetted bottom, the length ofeach of said bottom folds being less than the width of the bag, thegussetted bottom being adapted to unfold and lie flat when the bag ispacked, the lower portion of each wall below the level of said centralfold and the respective underlying gusset panel each having end edges ateach end thereof extending from the respective end of the respectivebottom fold at an angle thereto upwardly and outwardly to a point spacedinwardly from the respective side of the bag and below the level of saidcentral fold and heabsealed together to form angled end edge seals, andfurther having heat-sealed tab-forming edge portions between said pointand the respective side edge of the bag, said bag, when packed, having agenerally rectangular flat bottom formation constituted by the portionof the two gusset panels between said bottom folds unfolded and lyingflat therebetween and side panels extending up from the ends of saidbottom formation, with the said angled end edge seals extending upwardlyand converging toward one another from the corners of said rectangularbottom formation at the lower end of each of said side panels, andfurther having a tab constituted by the portions of the bag walls andgusset panels bounded by the said heat-sealed tabforming edge portionsoverlying the side panel at the upper end of said angle edge sealsadapted to be grasped and pulled up to tear the bag open along the sidepanel, and said bag having heat-seal-inhibiting material on that surfaceof one of the gusset panels which faces the other gusset panel.

5. A bag as set forth in claim. ll wherein said heatsealed tab-formingedge portions are inclined slightly upwardly and outwardly from saidpoints to the side edges of j the bag.

6. A bag made of head-scalable sheet plastic material having a gussettedbottom comprising two opposed gusset panels each joined to a respectivewall of the bag at a bottom fold and extending upwardly from the bottomfolds between said walls and joined together at their top by a foldconstituting the central fold of the gussetted bottom, the length ofeach of said bottom folds being less than the width of the bag, thegussetted bottom being adapted to unfold and lie flat when the bag ispacked, the lower portion of each wall below the level of said centralfold and the respective underlying gusset panel each having end edges ateach end thereof extending from the respective end of the. respectivebottomv fold at an angle thereto upwardly and outwardly to a pointspaced inwardly from the respective side of the bag and below the levelof said central fold and heat-sealed together to form angled end edgeseals, and further having heat-sealed tab-forming edge portions betweensaid point and the respective side edge of the bag, said bag, whenpacked, having a generally rectangular flat bottom formation constitutedby the portion of the two gusset panels between said bottom foldsunfolded and lying flat therebetween and side panels extending up fromthe ends of said bottom formation, with the said angled end edge sealsextending upwardly and converging toward one another from the corners ofof said rectangular bottom formation at the lower end of each ofsaidside panels, and further having a tab constituted by the portions ofthe bag walls and gusset panels bounded by the said heat-sealedtabforming edge portions overlying the side panel at the upper end ofsaid angled edge seals adapted to be grasped and pulled up to tear thebag open along the side panel, said heat-sealed tab-forming edgeportions being inclined slightly upwardly and outwardly from said pointsto the side edges of the bag, and said bag having heat-seals at bothsides and a stripe of heat-sealinhibiting material on that surface ofone of the gusset panels which faces the other gusset panel, said stripehaving one edge thereof extending along the fold at the bottom of saidone gusset panel and its other edge at a level between the level of saidpoints and the lower ends of said side seals.

7. A bag as set forth in claim 2 wherein said edge portions between saidpoints and the side edges of the bag are parallel to the bag ends.

8. A bag as set forth in claim 7 having heat-seals at both sides and astripe of he'at-seal-inhibiting material on that surface of one of thegusset panels which faces the other gusset panel, said stripe having oneedge thereof extending along the bottom fold at the bottom of said onegusset panel and its other edge at a level above said heat-sealedtab-forming edge portions and terminating short of said side seals.

1. A bag made of heat-sealable sheet plastic material having a gussettedbottom comprising two opposed gusset panels each joined to a respectivewall of the bag at a bottom fold and extending upwardly from the bottomfolds between said walls and joined together at their top by a foldconstituting the central fold of the gussetted bottom, the length ofeach of said bottom folds being less than the width of the bag, thegussetted bottom being adapted to unfold and lie flat when the bag ispacked, the lower portion of each wall below the level of said centralfold and the respective underlying gusset panel each having end edges ateach end thereof extending from the respective end of the respectivebottom fold at an angle thereto upwardly and outwardly to a point spacedinwardly from the respective side of the bag and below the level of saidcentral fold and heat-sealed together to form angled end edge seals,said opposed gusset panels being free from one another between saidbottom folds and said points and further having heat-sealed tab-formingedge portions between said point and the respective side edge of thebag, said bag, when packed, having a generally rectangular flat bottomformation constituted by the portion of the two gusset panels betweensaid bottom folds unfolded and lying flat therebetween and side panelsextending up from the ends of said bottom formation, with the saidangled end edge seals extending upwardly and converging toward oneanother from the corners of said rectangular bottom formation at thelower end of each of said side panels, and further having a tabconstituted by the portions of the bag walls and gusset panels boundedby the said heat-sealed tab-forming edge portions overlying the sidepanel at the upper end of said angled edge seals adapted to be graspedand pulled up to tear the bag open along the side panel.
 2. A bag as setforth in claim 1 wherein the bag has heat-seals at both sides.
 3. A bagas Set forth in claim 1 wherein said angled seals are inclined at anangle of 45* to the line of the bottom folds.
 4. A bag made ofheat-sealable sheet plastic material having a gussetted bottomcomprising two opposed gusset panels each joined to a respective wall ofthe bag at a bottom fold and extending upwardly from the bottom foldsbetween said walls and joined together at their top by a foldconstituting the central fold of the gussetted bottom, the length ofeach of said bottom folds being less than the width of the bag, thegussetted bottom being adapted to unfold and lie flat when the bag ispacked, the lower portion of each wall below the level of said centralfold and the respective underlying gusset panel each having end edges ateach end thereof extending from the respective end of the respectivebottom fold at an angle thereto upwardly and outwardly to a point spacedinwardly from the respective side of the bag and below the level of saidcentral fold and heat-sealed together to form angled end edge seals, andfurther having heat-sealed tab-forming edge portions between said pointand the respective side edge of the bag, said bag, when packed, having agenerally rectangular flat bottom formation constituted by the portionof the two gusset panels between said bottom folds unfolded and lyingflat therebetween and side panels extending up from the ends of saidbottom formation, with the said angled end edge seals extending upwardlyand converging toward one another from the corners of said rectangularbottom formation at the lower end of each of said side panels, andfurther having a tab constituted by the portions of the bag walls andgusset panels bounded by the said heat-sealed tab-forming edge portionsoverlying the side panel at the upper end of said angle edge sealsadapted to be grasped and pulled up to tear the bag open along the sidepanel, and said bag having heat-seal-inhibiting material on that surfaceof one of the gusset panels which faces the other gusset panel.
 5. A bagas set forth in claim 1 wherein said heat-sealed tab-forming edgeportions are inclined slightly upwardly and outwardly from said pointsto the side edges of the bag.
 6. A bag made of head-sealable sheetplastic material having a gussetted bottom comprising two opposed gussetpanels each joined to a respective wall of the bag at a bottom fold andextending upwardly from the bottom folds between said walls and joinedtogether at their top by a fold constituting the central fold of thegussetted bottom, the length of each of said bottom folds being lessthan the width of the bag, the gussetted bottom being adapted to unfoldand lie flat when the bag is packed, the lower portion of each wallbelow the level of said central fold and the respective underlyinggusset panel each having end edges at each end thereof extending fromthe respective end of the respective bottom fold at an angle theretoupwardly and outwardly to a point spaced inwardly from the respectiveside of the bag and below the level of said central fold and heat-sealedtogether to form angled end edge seals, and further having heat-sealedtab-forming edge portions between said point and the respective sideedge of the bag, said bag, when packed, having a generally rectangularflat bottom formation constituted by the portion of the two gussetpanels between said bottom folds unfolded and lying flat therebetweenand side panels extending up from the ends of said bottom formation,with the said angled end edge seals extending upwardly and convergingtoward one another from the corners of of said rectangular bottomformation at the lower end of each of said side panels, and furtherhaving a tab constituted by the portions of the bag walls and gussetpanels bounded by the said heat-sealed tab-forming edge portionsoverlying the side panel at the upper end of said angled edge sealsadapted to be grasped and pulled up to tear the bag open along the sidepanel, said heat-sealed tab-forming edge portions bEing inclinedslightly upwardly and outwardly from said points to the side edges ofthe bag, and said bag having heat-seals at both sides and a stripe ofheat-seal-inhibiting material on that surface of one of the gussetpanels which faces the other gusset panel, said stripe having one edgethereof extending along the fold at the bottom of said one gusset paneland its other edge at a level between the level of said points and thelower ends of said side seals.
 7. A bag as set forth in claim 2 whereinsaid edge portions between said points and the side edges of the bag areparallel to the bag ends.
 8. A bag as set forth in claim 7 havingheat-seals at both sides and a stripe of heat-seal-inhibiting materialon that surface of one of the gusset panels which faces the other gussetpanel, said stripe having one edge thereof extending along the bottomfold at the bottom of said one gusset panel and its other edge at alevel above said heat-sealed tab-forming edge portions and terminatingshort of said side seals.